The Effect of the Method of Compensation on Hydrostatic Bearing Stiffness

Capillary, orifice, and flow control valve compensation of hydrostatic thrust bearings is investigated theoretically with regard to the effect of these three methods of compensation on the stiffness of the lubricant film. Equations are derived which permit rapid determination of bearing stiffness at any given load and film thickness. When a hydrostatic bearing is made to operate at any given film thickness and load, it is found that at this load and film thickness no adjustment of the compensating element or supply pressure will alter the fact that ψ_valve > ψ_orifice > ψ_capillary where ψ equals the absolute value of stiffness. Furthermore, with fixed supply pressure and compensation, this stiffness relationship will remain the same for all practical values of load above and below the initial film thickness-load point.